ABSTRACT
This article reported a case of nemaline myopathy caused by KLHL40 gene complex heterozygous mutations. This baby girl presented with shortness of breath, low myodynamia, and low muscle tension immediately after birth. However, her symptoms became worse after conventional treatment. Physical examination found lower muscle strength and muscle tone in four limbs and no primitive reflexes. The biochemistry test showed increased serum creatine kinase (CK). A muscle biopsy was not performed. The second-generation gene test confirmed the KLHL40 gene complex heterozygous mutations, which was a known mutation c.932G>T (p.R311L) and a de novo mutation c.1487T>A (p.M496K), inherited from the father and mother, respectively. Nemaline myopathy is a rare congenital muscular disease characterized by nemaline bodies in muscle fibers. Pathological and genetic diagnoses are the gold standards for the diagnosis of this disease.